A method for continuous measurement of the surface temperature of the part of the wall of the respective unit which is not in contact with the melt and of the progressively worn refractory lining is known. In this method the heated surface of a heat conductive body and the internal surface of the refractory lining are heated in the same conditions under the action of one and the same heat flow. The temperatures along the heat conductive body are measured with sensors, the signals of these sensors being connected at the same time with a measuring and a logic diagnostic circuit into a module for process interface. In the logic circuit there are checked the soundness of the respective temperature sensor and generated logic signals for indication of its functional state, which depends on the degree of wear of the lining and serves for measuring the thickness also in descrete moments, being determined accurately by the failure of the end sensor.
The drawbacks of this known method lie in the impossibility to use it for measuring the temperature of strongly active and high-temperature melts, as well as in that the thickness of the refractory lining is determined exactly only when failure of the thermoelectric sensor occurs.
An apparatus for combined measurement of the surface temperature and the thickness of the refractory lining and of the heat flow through it is known. This apparatus comprises thermoelectric sensors incorporated in a body with a heat transfer coefficient greater than the heat transfer coefficient of the refractory lining, located at different depths in the lining and connected by means of a standardizing converter and a measuring circuit to the input of a commutator, connected with the computing module by means of a block for digital interface, and to the measuring circuit there is connected a logic diagnostic circuit connected with the computing module, which consists of a filtration block for the input measurements, a block for the input memory connected to a block for automatic calibration and to a commutator for process interface.
The drawbacks of the described apparatus lie in its inapplicability for determining the temperature of strongly active high-temperature melts, in the great number of thermoelectric sensors which are irretrievably consumed during the process of measurement, in that the thickness of the refractory lining is determined accurately only by failure of the thermoelectric sensor.